QSlider::groove:horizontal {
    height: 4px;
    background: #e0e0e0;
    border-radius: 2px;
}
QSlider::handle:horizontal {
    background: #0078d4;
    border: 2px solid white;
    width: 16px;
    height: 16px;
    margin: -6px 0;
    border-radius: 8px;
}
QSlider::handle:horizontal:hover {
    background: #106ebe;
}
QSlider::sub-page:horizontal {
    background: #0078d4;
    border-radius: 2px;
}